Thermoelectric materials can be utilized in a variety of industrial applications including high quality power generation devices and cooling devices. They can also be used in solar conversion and extraction of automotive or industrial waste heat. The thermoelectric properties of any material can be characterized by a quantity called figure of merit Z (or dimensionless figure of merit ZT), defined as Z=S2σ/k, where S is Seebeck coefficient, σ is electrical conductivity, and k is total thermal conductivity. It is desirable to construct materials with high ZT values (e.g., having low thermal conductivity k and/or high power factor S2σ). Accordingly, researchers continue to seek to produce materials that exhibit superior ZT values.
Skutterudites are a potentially attractive class of substances that might be used in producing thermoelectric materials. They typically exhibit outstanding electrical properties, including high electrical charge mobilities and substantial Seebeck coefficients—which can result in high power factors. Unfortunately, they also often exhibit high thermal conductivities, which can limit the overall ZT value that can be achieved by a thermoelectric material.
Accordingly, the need persists to develop thermoelectric materials that exhibit attractive performance properties, including materials that may be related to skutterudites.